In conventional elevator diagnosing devices, there is known an elevator diagnosing device in which slippage detection means for detecting a slippage amount between a drive pulley and a main cable is provided, an elevator control device performs, at the time of elevator diagnosis, rotation control of a hoisting machine based on an elevator diagnosis speed pattern, the acceleration/deceleration of the drive pulley in which is more than that of a normal speed pattern, detects the slippage amount using the slippage detection means, and performs diagnosis to determine whether or not friction between the drive pulley and the main cable is reduced based on the detected slippage amount (see, e.g., PTL 1).
In addition, in conventional elevator diagnosing devices, there is also known an elevator diagnosing device in which a first encoder disposed in a motor as motor operation monitoring means for monitoring the operational status of the motor that rotates a sheave and a second encoder disposed in a speed governor as elevating speed measurement means for measuring an elevating speed of a car are provided, a difference between a rope feed speed of the sheave based on the operational status of the motor monitored via the motor operation monitoring means and the elevating speed of the car based on a signal from the elevating speed measurement means is calculated as a rope slip speed, and the operation of the car is suspended when the rope slip speed exceeds a predetermined speed (see, e.g., PTL 2).